A variety of applications employ fluid filter assemblies. Such applications include, for example, hydraulic systems, fuel delivery systems, coolant systems, and engine lubrication systems. Filter assemblies may be used to filter any type of fluid, such as, for example, air, gasoline, diesel fuel, lubricating oil, water, coolant fluid, and others. Air filtration products in particular are used in a variety of such applications, such as for example in the turbo engine components of a vehicle engine.
Conventional fluid filter assemblies may include a filter media, such as a sheet of fibrous filter material. In exemplary configurations, the filter media may be fluted, or folded to form a plurality of parallel pleats or folds. The filter element may be received within in a filter housing, which is capped by a filter head or filter cover. In an example of an air filter assembly, air flows through an inlet in the filter head, through the filter media, and out through an outlet of the filter housing. The inlet and outlet passages in the filter head and/or filter housing direct fluid flow, such as air flow, into and out of the filter element. The air or other fluid passes through the filter element, which separates particles and other contaminants from the fluid which is then returned to the operating system. In order for the filter element to properly function and not leak, a positive seal must be maintained with the filter head and filter housing. Typically, air filter elements use an o-ring supported seal along a plane in a straight cut or radial seal gland design. A sloped or angled seal gland design has been used, for example, as shown in U.S. Pat. No. 7,494,017 for “Filter Element With Off-Axis End Cap”, issued to the assignee of the present application. Another example of filter sealing is shown in U.S. Pat. No. 8,916,044 entitled “Filter Element Wave Gland Seal,” also issued to the assignee of the present application.
There remains potential for improvement, however, in achieving effective sealing with sufficient filtration capacity, while maintaining ease of installation and replacement of the filter element. There also have been issues of high cost in connection with manufacturing various filtration products, and air filtration products in particular. Previously, the filter element had been designed as an injection molded plastic lower cover with a co-injection molded seal. Although generally effective, such manufacturing process of a co-injection molded cover and seal elements has been somewhat costly.